After pressing start, navigate among the different categories by pressing the buttons on the top. When you are done choosing your dragon's appearance, press the arrow in the top right to go to the sliders that change the colors. Drag and drop: If you decide you no longer want something you have dragged out, drag it back to the white bar on the side.
Thanks so much to @fallingstars5 for the original project, I was going to make one of these eventually but wasn't sure how, so thanks so much! As per usual, no hate comments.